Machine and method for purifying the inert gases



. R. H. SAVAGE 2,624,421

MACHINE AND METHOD FOR PURIFYING THE INERT GASES Jan. 6, 1953 Filed Aug.12, 1948 3 V. p 4 .a e r m Fv n w u 0a r 1. z m o t F 5 e 3 O u S H z su e v a u w h v m. w .6. m II a M w 0 5/. R. M r m v v argon is a goodexample.

the nitrogen by the activated charcoal only.35

machine for the production of'these fine chemi- Patented Jan. 6, 1953 7UN TE STATES PATE T" oFFicE rnn men's GASES j h MACI1INEAND1\IETHODFort-roams York ' 1 Robert H. Savage, Sootia, N. Y.,-assignor Gen: joral Ele tri C ta s. @mrationoi' New Application August 12, 194;, SerialNo. 43,855,

My invention relates to th purification oi the Inert gasesand moreparticularly to a machine and method ior removing from the inert gases,

- traces or appreciable quantities. or gases other than the rare gases.I The subject matter of this application is closely related .to thesubject matter contained in my copending application; Serial No. 43,854filed poncurrently herewith entitled Chemically Active Graphitic 'CarbonPowder "and Apparatus for 10 Making Same" and copending divisional applcations of the above application, Serial No. 102,213, I entitled Processof Making Chemically Active Graphite Carbon Powder and Serial No.102,214,

entitled Chemically Active .Graphitic Carbon Powder, all assigned to thesame assignee'as the present invention. i In the production of the inertgases, the methods of which are well known in the art, it is verydimcult to producethe. final product free of such impurities ashydrogen, nitrogen, methane, C0, C02, oxygen, and others. In an effortto purify the inert gases many procedures and machines havebeendeveloped. One of these is the adsorption method which utilizesactivated charcoal at low temperatures.

The impurity that is most diiilcult to remove from the inert gases isnitrogen and is primarily so because nitrogen is a relatively inactivegas.

Activated charcoal not only adsorbs nitrogen but also adsorbs some ofthe inert gases and one of the inert gases adsorbed is argon. Thus, theproblem of separation of nitrogen from The adsorption of takes place atlow temperatures and, does not eiIect a quantitative separation ofnitrogen from argon because the adsorption is physical (non-chemical) innature and does not easily distinguish between two gases having boiling40 points as close together as are those of nitrogen and argon. Afterthe adsorption of nitrogen and.

argon by the activated charcoal. fractionaldistiL- lation must beresorted to in order to separate the two gases. With the development ofsuch a to in my copending applications mentioned above, thepossibilities of. purification of the rare inert gases are greatlyenhanced. The method and cally active particles is fully described andclaimed in my copending applications referred to above. It has beenfound that at room temperatures these particles of chemically activegraphite selectively and irreversibly adsorbnitroge'n in the 5 5presence of argon at the rate. of 0.2 cc. per .gram (STP), leaving theargonunaflected; whereas in the physical adsorption by chilled charcoal,both nitrogen and. argon are adsorbed and fractional separation bydistillation is required.

product as the chemically active graphite referred -1 24 Claims.' (01.lac-4.3

Although methods exist for the selective ad-' sorption of hydrogen,these methods have very -low rates of adsorption. It has been found thatthe particles of chemically active graphite selectively and irreversiblyadsorb hydrogen at the rate of about 2 cc. (STP) per gram of chemicallyactive graphite and this rate of adsorption is.

many times greater than the rate of adsorption or any other knowncarbon. These chemically active graphite particles will, in thepresence'of inert gases, selectively and irreversibly adsorb gases suchas methane, C0, C02, oxygen, and others.

- Thus, one of the objectsof my inventidn is to provide a new machineand a new method for the purification of the inert gases. I

Another object 01' my invention is to provide a machine and a method forthe purification of the inert gases at ordinary room temperatures.

Another object of my invention is to provide a machine and a method forextracting traces of hydrogen, nitrogen, methane, C0, Con 02 and othergases from theinert gases.

Further objects and advantages of my invention will become apparent as.the following description proceeds and the features'of 'novelty' whichcharacterize my invention will be pointed outwith particularity in theclaims annexed to shown as shaft 5 to which is coupled one-hall of amagnetic coupling 6 which is also contained within the gas-tight chamberl. Mounted on wall I of chamber I are the guide and feed means fordirecting a graphite rod 8 against the surface of the comminuting wheel2. The guide means is shown as consisting of a collar 9 which is weldedon to wall I so .thatthe Joint will be gas tight. Collar 9 extendspastwall I into chamber I so as to better guide thegra'phite rod 8 after ithas been reduced in-length during operation ot'the machine. The collar 9is threaded III at its outside so as to receive an end cap I Land aresilient gasket I2 is provided to make the joint gas tight. Within thecollar 9 and cooperating with the graphite rod 8 are a .spring.l3 and'aweight It for exerting a constant pressure on the "rii'phite rod.Since wall I of the chamber is removablea resilient gasket I5 isprovided to make the joint gas tight.

, co The second half of the magnetic coupling I is The comminuting wheelis,

"the chamber the and" gas-tigh by means of gas-tight line I! is theimpure gas,

system whose elements. will now be described.

Thelmpure gas, which is the ordinary commercial product, com'esin tanksor bombs. I have shown V a container 28 for impure gas connected to adrier 2I andseparated by a valve 22. The gas leaving the drier 2I iscompressed by ,a pump oncompressor 23 and is stored in gas tank 24 whoseinlet and outlet are both controlled by valves 25 and 28.- A by-passsystem 21' is provided directly from the drier 2| to the gas-tightchamberI with a valve 28 interposed in the line. Within the chamber I isprovided a set 01. baille plates 28 for the purpose of providing a mazewhich will prevent the moving gasirom transporting out" or finewear-dustparticles located therein. I

,Ported to the chamber I. by means or a gas.- tight line 38 is agas-tight system which is used both for evacuating-chamber-I and alsofor col ,l'ecting the purified rare inert gases. I have shown a branchof this system 3| leading. to a vacuum pump 82 and a valve 28. forclosing off this branch of the gas line. I have also shown a' purgingoutlet 34 and a valve 85 interposed between it and they gas line 30. Apressure gage 88 and a valve 81 are provided for measuring the pressurewithin the system. A reservoir 38 for the purified gas is provided inthe gas-tight system and valve 38 x is interposed between the tank andthe remainder of the gas system. Connected to the reservoir 88 for thepurified gas is a pump or compressor M and a valve 42 is supplied attheoutlet oi the pump 4I said valve-42 being adapted to fit gas not,take place and, such non-lubricating gases are dry air, or a dry gas ofthe inert (e. g. argon) The chemically active graphitic carbon powderadsorbsthe traces or small amounts of the impurities such as hydrogenandv nitrogen which are mixed with and contaminate the inert gas.-

as group As was described hereinbefore this adsorption is irreversibleand the purified gas is now passed -through the maze formed by theplurality of bafile plates 29 which serve to settle out the particles ofgraphite that are. carried along by the gas and then the purified gas iscaptured in reservoir 88. After valve 38 is closed valves 40 and 42 areopened and the compressor pumps the gas from tank 38, compresses it, andstores it ready for use in suitable containers such as tank 43.

A variation of this method is to purge chamber I with the impure gas. Todo this valves 38 and 20 are opened and some of the high ressure, dry,impure gas stored in tank 24 is permitted to enter and purge chamber Iby driving out the gases After the system is purged oi located therein.the residual gases that were in chamber I the valves are closed and theprocess that was described above is begun.

If the source of impure gas is pressurized, then I the compressor 23 andpressurized storage tank bottles flwhich are to be filled with-the compressed purified rare inert gas.

The base surface 44 of the gas-tight chamber is shaped so aslto form aconical section 45 below the comminuting wheel which serves as ameans ofcollecting thechemically active graphitic carbon powder 48 which isproduced within the chamber. Threaded to the cylindrical'extension 41 orconical section is a plug 48, which seals chamber I. Removal of plug 48provides a means or cleaning out thegraphitic carbon powder irom thegas-tight chamber. A resilient gasket 48 is between members 48 providedto keep the joint A number of modes of operation of the machine arepossible and a number oi! these modes are described "herein. 'In thefirst, all the valvesin thetwo gas-tight piping systems are closedexcept valve 28. The vacuum pump 82 is operated "to evacuatelchamber Iafter which valve 38 is I through chamber I. Simultaneously with this,or

at sometime previous tothe opening oi valves 28 and 38, the commlnutionprocess is begun by starting up: motor I8 and by transmitting the rotarymotion to" the comminuting surface 2 via the magnetic clutch. Thegraphite, when bearing upon a rotating surface located in an evacuatedchamber or in a chamber filled with a non- Whereupon, the valves arelubricating gas, seizes and is comminuted to form the chemically activegraphitic carbonpowder described and claimed in 'my copendingapplication referred to above. A non-lubricating gas 24 may beby-passed. In that way the dried gas passes through line 21 directly tochamber I where it is purified and is then extracted through line 28.The purified gas system may be varied by either eliminating tank 38 anddirectly compressing the purified product or by eliminating com pressor-H and storage tank 43, and by capturing andstoring the purified gas inreservoir 38. Also,

by operating both compressors 23 and 4i, and by having a multiplicity ofinlet and outlet connections theprocess can be made continuous. The

process can be regulated so as to purify only a certain amount of gas byvarying the amount of gas permitted to enter chamber I and by operatingthe compressors so' that only a certain amount of gas enters and leaveschamber I.

To replenish the supply or graphite,al1 the valves are closed, cap I2 istaken ofl and weight I4 and spring I3 are removed. A new stick orgraphite is inserted in collar 8 and all the parts are reassembled.

While I have shown aparticular embodiment of my invention, it will beunderstood, or course, that I do not wish to be limited thereto sincemany modifications may be made, and I therefore contemplate by theappended claims to cover any modifications as fall within the truespirit and scope or my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is;

-l. A meth impurities con ined therein, consisting of gases other thanthe inert gases, comprising the step of subjecting the gas mixture toactivated adsorption by chemically, active, selectively adsorp-- tive,ultra-fine graphite particles. 1

2-. A method for removing other gases from the inert gases comprisingthe steps or drying the gas mixture, and then subjecting the gasmixtureto activated adsorption by chemically active ultra-fine'graphiteparticles,

' '3. A method for separating relatively pure inert gases from mixturescontaining gases other than the inert gases, comprising the steps'oi'dry-'- ing the gas-mixture, subjecting the gas mixture to activatedadsorption by chemically active isonein whose presencegraphitelubricationwill 76' ultra-fine graphi M Ill ior' removing from the inertgases.

- ite.

the impure inert inert gases containing than 'ing the gas'inixture,subjecting the ga mixture to activated adsorption at a controlledpressure' bychemically active ultra-fine graphite particles, compressingthe purified gas and storing it in pressurized containers.

5. A method for separating relatively pure inert gases from mixturescontaining gases other than the inert gases comprisingthe steps of sub-Jecting the gas mixture at sub-atmospheric pressure to activatedadsorption by chemically active ultra-fine graphite particles, and thencompressing the purified gas and storing it in pressurized containers.

6. A method for removing gaseous impurities from mixtures of theinert'gases containing such impurities comprising the steps ofevacuating a gas-tight chamber. comminuting graphite within said chamberin the presence of a nonlubricating gas so as to produce chemicallyactive ultra -fine graphite particles capable of activated adsorption,and contacting said comminuted graphite with the impure inert gasmixture whereby the impurities in said gas mixture are subjected toactivated adsorption by said comminuted graph- 'l. A method forpurifying a mixture of' the inert gases containing as impurities. gasesother than the inert gases, comprising the steps of. evacuating agas-tight chamber, comminutinggraphite within said chamber in thepresence of a nonlubricating gas. drying the impure inert gas, andcontacting said comminuted graphite with gas mixture whereby theimpurities of said gas mixture are subjected to activated adsorption bysaid comminuted graphite. 8. A method for purifying a mixture of the asimpurities gases other than the inertgases, evacuating a gas-tightchamber, then comminuting graphite within said chamber in the presenceof a nonlubricating gas so asto produce chemically active ultra-finegraphiteparticles, then dry ing the impure inert gas, bleeding theimpure gas into the purifying chamber at a controlled. gas pressure,maintaining the flow of the gas through the chamber so the chemicallyactive ultra-fine graphite particles produced by the comminution processand the impurities are removed from the gas by adsorption on thegraphite.

9. A method for purifying a mixture of the.

inert gases containing as impurities gases other the inert gases,comprising the steps of evacuating a gas-tight chamber, then comminutinggraphite within said, chamber in the presence of a nonlubricating gas soas to produce chemically active ultra-fine graphite particles. thendrying the impureinert'gas, bleeding the impure gas into the purifiedchamber at a controlled sub-atmospheric gas pressure, maintaining thenow of the gas through the chamber so that it comes into contact withthe chemically that it comes into contact with a than the inert 881888,.comprising the steps or evacuating a gas-tight chamber, then comminutinggraphite. within said chamber in the presence of a nonlubricating gas soas to pro duce chemically active ultra-fine graphite particles, thendrying the impure inert gas, bleeding the impure gas into-nthe purifiedchamber at a controlled sub-atmospheric gas pressure, maintaining thefiow of the gas through the chamber so that it comes into contact withthe chemically active ultra-fine graphite particles produced by thecomminution process, separating the impurities from the gas mixture byactivated adsorption on the graphite, passing the gas through a maze ofpassages, capturing the puri- K fled gas in a container, and thencompressing the comprising the steps of I tainers.

purified gas and storing it in pressurized con- 11. A method forpurifying the inert gases comprising the steps of drying the impureinert gas, compressing the dried gas, bleeding the impure gas at acontrolled pressure into a as-tight purifying chamber containingchemically active ultra-fine graphite particles whereby .said gas issubjected'to activated adsorption. and, maintaining the flow of the gasthrough said chamber so that all the gas comes into contact with thechemically active graphite particles whereby impurities in the gas areremoved by adsorption on the graphite.

12. A method for purifying the inert gases comprising the steps ofdrying the impure inert gas, compressing the dried gas, bleeding theimpure gas at a controlled pressure into a gas-tight purifying chambercontaining chemically active ultra-fine graphite particles whereby saidgas is comprising the steps of drying the impure inert gas, bleeding theimpure gas at a controlled subatmospheric pressure into a gas-tightpurifying I chamber containing chemically active ultra-fine graphiteparticles whereby said gas is subjected to activated adsorption,maintaining the fiow of the gas through said chamber so that all the gasactive ultra-fine graphite particles produced bythe comminution comesinto contact with the chemically active graphite particles, separatingthe impuritiesfrom the gas mixture by adsorption on the graphite.passing the gas through a maze of passages, capturing the purified gasin a container, and then compressing the purified gas and storing it inpressurized containers.

. 14. A method for purifying a mixture of the rare inert gasescontaining as impurities gases other than the inert gases comprising thesteps of purging a gas-tight purifying chamber with g anonlubricatingdry inert gas, then comminuting graphite in the presenceof said nonlubricating gas so as to produce chemically active ultra-finegraphite particles, bleeding the impure gas at a controlled pressureinto the purifying chamber,

separating the impurities from the gas mixture the graphite, andmaintaining by adsorption on the fiow of the gas through the chamber sothat all the gas comes into contact with the chemically activeultra-fine graphite particles produced by the comminution process.

15. A method for purifying a rare inert gases containing as impuritiesgases mixture of the k graphite in the presence of said nonlubricating'gas so as to produce chemically active ultra-fine graphite particles,bleeding the impure gas at a controlled pressure into the purifyingchamber, separating the impurities from the gas mixture by adsorption onthe graphite, maintaining the fiow of the gas through the chamber'sothat all the gas comes into contact with the chemically activeultra-fine graphite particles produced by the comminution process,passing the purified gas through a maze of passages, and then storingthe purified gas in a container.

16. A method for purifying a mlxture'of the rare inert gases containingas impurities gases other than the inert gases, comprising the steps ofdrying the impure inert gas, compressing the dried gas, storing thecompressed dried gas in a tank, then purging a. gas-tight purifyingchamber with the compressed inert gas, then comminuting graphite withinsaid purifying chamber in the presence of said dried gas so as'toproduce chemically active ultra-fine graphite particles, then bleedingthe impure gas at sub-atmospheric pressure into the purifying chamber,

separating the impurities from the gas mixture by adsorption on thegraphite, and maintaining the flow of the gas through the chamber sothat it comes into contact with the chemically active graphite particlescontained within said chamber.

17. A method for purifying a mixture of the rare inert gases containingas impurities gases other than the inert gases, comprising th steps ofdrying the impure inert gas, compressing the dried gas, storing thecompressed dried gas in a tank, then purging a. gas-tight purifyingchamber with compressed inert gas, than comminuting graphite within saidpurifying chamber in the presence of said dried gas so as to producechemically active ultra-fine graphite particles, then bleeding theimpure gas into the purifying chamber, separating the impurities fromthe gas mixture by adsorption on the graphite, maintaining the flow ofthe gas through the chamber so that it comes into contact with thechemically active graphite particles contained within said chamber, thenpassing the gas through a maze of passages, and then storing the gas incontainers.

18. A method for purifying the inert gases comprising the steps ofpurging a gas-tight purilubricating gas so as to produce chemicallyactive ultra-fine graphite particles, and then contacting said graphiteparticles with the impure gas whereby said gas is subjected to activatedadsorption on said particles and the impurities are separated therefrom.

20. A machine for removing gaseous impurities from the inert gasescomprising a gas-tight housing, comminuting means for oomminutinggraphitic carbon mounted within said housing, means for evacuating saidhousing, means for introducing the inert gas to be purified into saidhousing whereby said impure gas comes into contact with the comminutedgraphite, and means for collecting the purified inert gas.

21. A machine for removing gaseous impurities from inert gasescomprising a gas-tight housing, comminuting means for comminutinggraphitic carbon mounted within said housing,

means for purging said housing with the inert gas whereby said housingbecomes filled with only the inert gas, means for feeding the inert gasto be purified into said housing whereby said impure gas comes intocontact with the comminuted graphite, and means for collecting thepurified inert gas.

22. A machine for removing gaseous impurities from the inert gasescomprising a gas-tight housing, comminuting means for comminutinggraphitic carbon mounted within said housing, means for evacuating saidhousing, means for feeding the inert gas to be purified into saidhousing whereby saidimpure gas comes into contact with the comminutedgraphite, means for separating the purified inert gas from the productsof comminution, and means for collecting the purified inert gas.

23. A machine for removing gaseous impurities from the inert gasescomprising a gas-tight housing, comminuting means for comminutinggraphitic carbon mounted within said housing, means for evacuating saidhousing, means for feeding the inert gas to' be purified into saidhousing whereby said impure gas come into contact with the comminutedgraphite, means comprising a maze for separating the purified inert gasfrom the products of comminution, and means for collecting the purifiedinert gas.

24. A machine for removing gaseous impurities from the inert gasescomprising a gas-tight housing, comminuting means for comminutinggraphitic carbon mounted within said housing, means for purging saidhousing with the inert gas whereby said housing becomes filled with onlythe inert gas,.mean for feeding the inert gas to be purified into saidhousing whereby said impure gas comes into contact with the comminutedgraphite, means for separating the purified inert gas from the productsof comminution, and means for collecting the purified inert gas.

, ROBERT H. SAVAGE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,782,493 Van Loon Nov. 25, 19301,937,446 Stampe Nov. 28, 1933 2,019,632 Ray Nov. 5, 1935 2,037,685Holden Apr. 14, 1936 2,386,366 Storment Oct. 9, 1945 OTHER REFERENCESCharcoal As An Adsorbent, by Garner, Natural Gas, vol. No. 11 ofNovember 1924, page 48.

Adsorption," by Mantell, Chemical Engineering Series 1945, McGraw-HlllBook Co. Inc., New York.

Industrial Carbon, by Mantell, 2d. Ed, 1946, D. Van Nostrand Co. Inc,New York.

1. A METHOD FOR REMOVING FROM THE INERT GASES IMPURITIES CONTAINEDTHEREIN, CONSISTING OF GASES OTHER THAN THE INERT GASES, COMPRISING THESTEP OF SUBJECTING THE GAS MIXTURE TO ACTIVATED ADSORPTION BY CHEMICALLYACTIVE, SELECTIVELY ADSORPTIVE, ULTRA-FINE GRAPHITE PARTICLES.